Die-set construction



y 1962 c. J. HRABAL 3,034,464

DIE-SET CONSTRUCTION Filed July so, 1958 United States Patent Qfifice3,934,464 Patented May 15, 1962 3,034,464 DIE-SET CONSTRUCTION CharlesJ. Hrabal, 429 Suwanee, Park Forest, Ill. Filed July 30, 1958, Ser. No.752,087 4 Claims. (Cl. 113-49) This invention relates to a die-setconstruction of the type utilized in metal stamping and formingoperations, and more particularly to new and improved means incorporatedin a die-set assembly for quickly and easily disassembling or removing apunch retainer or the like from a supporting plate without the need ofany special tools and without damaging or injuring any of the componentsof the die-set assembly.

It is generally the practice in the metal stamping and forming art toprovide a die-set assembly which includes a punch retainer. The punchretainer is rigidly attached to and accurately located upon a surface ofa supporting plate by means of a pair of pins and a pair of bolts. Thepins are fixedly carried by the punch retainer and are adapted to betightly pressed into blind holes accurately reamed and located in thesupporting plate. Of necessity the holes are blind holes and do notextend completely through the supporting plate. In a similar manner thebolts are engageable with threaded blind holes in the supporting plateto secure the punch retainer in place on the supporting plate.

oftentimes, for various reasons, the punch retainer must be removed fromand/ or relocated on the supporting plate. I-Ieretofore, there was noquick and easy way to remove the punch retainer from the supportingplate. It was necessary to first remove the two attaching bolts and thencarefully and simultaneously apply a force tending to separate the punchretainer from the supporting plate while tapping the punch retainer witha hammer or like. Inasmuch as the pins are disposed in blind holes, thepunch retainer cannot be removed by applying a force to the pin endsfrom the under or back side of the supporting plate. Since thesupporting plate having the pinreceiving holes therein is made ofrelatively soft material and the pins are hardened, the precision reamedholes often were enlarged and rendered inaccurate and useless forsubsequent employment during the punch retainer removal operation.Furthermore, a pin occasionally broke in the reamed hole whichnecessitated the additional difficult task of removing the broken pinportion from the supporting plate which diificult task was renderedextremely difiicult if the broken pin portion did not projectsufiiciently from the supporting plate to provide a grippable surface.While there are several methods commonly employed for removing brokenpin portions from the blind holes, all of them result in the destructionof the usefulness of the reamed holes since the holes no longer arecapable of accurately locating the punch retainer. It is therefore, animportant object of the present invention to obviate the above noteddisadvantages and shortcomings of prior die-set assemblies and toprovide a die-set construction wherein the punch retainer may be quicklyand easily removed from the supporting plate without the need of anyspecial tools, fixtures or the like and without damaging or injuring anyof the components of the die-set assembly including the locating pinsand the pin-receiving holes of the supporting plate.

A still further object is to provide a simple and inexpensiveconstructional modification of a conventional dieset assembly wherebythe punch retainer may be readily removed from the supporting plate witha minimum of effort.

Another object is to provide means for removing a .punch retainer from asupporting plate whereby the possibility of pin breakage and theenlargement of the pinreceiving holes during the removal operation, ismitigated considerably.

The foregoing and other important objects and desirable featuresinherent in and encompassed by the invention, together with the manypurposes and uses thereof, will become readily apparent from a readingof the ensuing description in conjunction with the annexed drawing, inwhich,

FIGURE 1 is a vertical sectional View of a portion of a die-set assemblyembodying the invention; and

FIGURE 2 is a plan view of the structure shown in FIGURE 1.

Referring to the drawing in detail, wherein like reference charactersrepresent like elements throughout the various views, a portion of adie-set assembly, designated generally by reference character 10, isshown. The die set assembly includes a supporting plate 11, partiallyshown, and a punch retainer 12 adapted to support a punch (not shown) ina conventional manner. When assembled, a back up plate 13 is interposedbetween the supporting plate 11 and the punch retainer 12.

As best shown in FIGURE 1, the supporting plate 11 is provided with apair of blind recesses or holes 14 therein which are employed foraccurately locating the punch retainer 12 on the supporting plate 11.The supporting plate 11 is also provided with a pair of internallythreaded blind holes or recesses 15. The blind holes 14 and 15 arearranged in a circle with each of the holes 14 being circumferentiallyspaced between the threaded blind holes 14.

The back up plate 13 which is sandwiched between the supporting plate 11and the punch retainer 12 has a plurality of spaced openings 16extending therethrough. The openings 16 have a diameter greater than theholes 14 and 15 and each opening is registerable with a respective hole14, 15 when the punch retainer 12, back up plate 13 and supporting plate11 are assembled together and in condition for use.

The punch retainer 12, which is adapted to support a punch element (notshown), has a pair of locating pins 17 secured thereto. The pins 17project from the normally bottom side of the punch retainer 12 and eachpin 17 is adapted to extend through an opening 16 of the back up plate13. When the punch retainer 12 is in its assembled condition the portionof each pin 17 projecting from the back up plate 13 is tightly pressedinto a respective blind hole 14, as shown in FIGURE 1. The punchretainer 12 is also provided with a pair of spaced holes 18 therethroughwhich are registerable with a respective pair of holes 16 of the back upplate 13 aligned with the internally threaded blind holes 15 of thesupporting plate 11. The die-set assembly includes a pair of attachingbolts 19, each of which is adapted to extend through a pair ofregistering holes 18, 16 and into threading engagement with the screwthreads of a respective blind hole 15 of the supporting plate 11.

When it is desired to remove the punch retainer 12 from the supportingplate 11 or to disassemble the dieset assembly, the attaching bolts 1are first unthreaded from the threaded holes 15 of the supporting plate11 and withdrawn from the holes 16 and 18 of the back up plate 13 andpunch retainer 12, respectively. Thereafter, one of the attaching bolts19 is inserted through an enlarged, central opening 21 formed throughthe punch retainer 12. When assembled, the enlarged, central hole 21 isin alignment with a threaded hole 20 in the back up plate 13. Thediameter of the hole 21 is the same as the diameters of the blind holes15 formed in the supporting plate 11 and the screw thread size and pitchformed in the hole 20 is the same as that provided on the attachingbolts 19. The attaching bolt 19 is then threaded into the hole 20 untilthe tip portion thereof engages the flat surface 22 of the supportingplate 11 which is in abutting engagement with the back up plate 13 whenthe die-set assembly is in its assembled condition, as shown inFIGURE 1. Continued rotation of the bolt 19 causes an axially directed,separation force to be exerted between the back up plate 1'3 (and thepunch retainer 12) and the supporting plate 11 and withdrawal of thepins 17 from the blind holes 14. Inasmuch as the pins 1'7 are spaced thesame distance from the longitudinal axis of the aligned holes 20 and 21it will be appreciated that the punch retainer 12 will be moved awayfrom the supporting plate 11 along the longitudinal axis of the alignedholes 20 and 21; Thus, neither the accurately positioned locating blindholes 14 nor the pins 17 are damaged during the disassembly operation.Furthermore, no special tools or the like are necessary to effect thedisassembly operation quickly and efliciently.

The embodiment of the invention chosen for the purposes of illustrationand description herein is that preferred for achieving the objects ofthe invention and developing the utility thereof in the most desirablemanner, due regard being had to existing factors of simplicity of designand construction, production methods, and the improvements sought to beefiected. It will be appreciated-therefore, that the particularstructural and functional aspects emphasized herein are not intended toexclude, but rather to suggest, such other adaptations and modificationsof the invention as fall within the spirit and scope of the invention asdefined in the appended claims.

What is claimed is:

1. In a die-set including a supporting member having a flat surface anda plurality of spaced blind holes opening into said flat surface,certain of said blind :holes serving as locating blind holes and theother blind holes having internal screw threads formed therein, saidblind holes being arranged in a circle with each of said locating blind'holes being circumferentially spaced between a pair of blind holeshaving screw threads formed therein; a back up plate overlying andabutting said fiat surface, sa d backup plate having a plurality ofspaced openings therethrough, each of said openings being alignable witha respective blind hole of said supporting member, said back up platefurther having a central aperture therethrough said central aperturebeing of the same diameter as said internally threaded blind holes, andhaving an internal screw thread of the same size as the screw threadformed in said threaded blind holes; a punch retainer overlying andabutting the surface of said back up plate opposite the surface thereofabutting said supporting member, said punch retainer having a centralopening alignable with said threaded aperture of said back up plate, thediameter of said central opening being larger than the threaded apertureof said back up plate, said punch retainer further having a plurality ofspaced apertures, each of said apertures being alignable with arespective opening of said back up plate, said punch retainer furtherhaving a plurality of locating pins fixed thereto, each of said pinsextending loosely through a respective opening in said back up plate andtightly into a respective locating blind hole in said supporting member,and means for selectively clamping said punch retainer to saidsupporting member or for moving said punch retainer away from saidsupporting member and withdrawing said pins from said locating blindholes including a threaded member, said threaded member beingalternatively insertable through a respective aperture of said punchretainer and the back up plate opening aligned therewith and intoengagement with the threaded blind hole of said supporting memberaligned with such opening or said central opening of said punch retainerand threaded aperture of said back up plate and into engagement withsaid fiat surface.

2. fln a die-set including a supporting member having a flat surface andtwo pairs of circularly spaced blind holes opening into said flatsurface, one pair of blind holes serving as locating blind holes and theother pair of blind holes having internal screw threads formed therein,each blind hole of one pair of blind holes being circumferentiallyspacedtbetween the blind holes of the other pair; a back up plateoverlying and abutting said fiat surface, said back up plate havingopenings therethrough, each of said openings being alignable with arespective blind hole of said supporting member, said back up platehaving a central aperture therethrough of the same diameter as saidthreaded blind holes and having internal screw threads of the same sizeas the screw threads of said threaded blind holes; a punch retaineroverlying and abutting the surface of said back up plate opposite thesurface thereof abutting said supporting member, and having a centralopening therethrough of larger diameter than and alignable with saidthreaded opening of said back up plate, said punch retainer having apair of apertures therethrough, each of said apertures being alignablewith a respective opening of said back up plate, said punch retainerfurther having a pair of locating pins fixed thereto, each of said pinsextending loosely through a respective opening in said back up plate andtightly into a respective locating blind hole of said supporting member;and means for selectively clamping said punch retainer to saidsupporting member or for moving said punch retainer away from saidsupporting member and withdrawing said pins from said locating blindholes including a threaded member, said threaded member beingalternately insertable through a respective punch retainer aperture andthe back up plate opening aligned therewith and into the threaded blindhole of said supporting member aligned with such opening or said centralopening of said punch retainer and central threaded aperture of saidback up plate and into engagement with said flat surface.

s 3. In a die-set including a supporting member provided with two pairsof circularly spa ced blind holes therein, one pair of blind holesserving as locating blind holes and the other pair of :blind holeshaving internal screw threads formed therein, each blind hole of onepair of blind holes being circumferentially spaced between the blindholes of the other pair; a back up plate overlying and abutting saidsupporting member and having a central opening therethrough of the samediameter as said threaded blind holes and having internal screw threadsformed therein of the same size as the screw threads of said threadedblind holes; a punch retaine overlying and abutting said back up plateand having a central opening therethrough of larger diameter than andalignable with said threaded aperture, said punch retainer having a pairof locating pins fixed thereto, each of said pins extending looselythrough said back up plate and tightly into a respective locating blindhole of said supporting memher; and means for selectively clamping saidpunch retainer to said supporting member or for moving said punchretainer away from said supporting member and withdrawing said pins fromsaid locating blind holes including a threaded member, said threadedmember being alternately insertable through said punch retainer and backup plate and into engagement with a respective threaded blind hole ofsaid supporting member or through said punch retainer central openingand into threading engagement with said back plate central threadedaperture and into abutting engagement with said supporting member.

4. In a die-set including a supporting member having a fiat surface,said member having a plurality of circu larly spaced locating blindholes and threaded blind holes therethrough opening into said flatsurface, each of said threaded blind holes being circumferentiallyspaced between a pair of locating blind holes; a :back up plateoverlying and abutting said flat surface having a plurality of spacedopenings therethrough, each of said openings being registerable with arespective blind hole of said supporting member, said back up platehaving a central threaded opening therethrough; a punch retainer havinga surface abutting a surface of said back up plate opposite the surfacethereof abutting said flat surface, said punch retainer having a centralopening of larger diameter than said back up plate central opening and aplurality of spaced attaching bolt-receiving openings therethrough, saidcentral opening being registerable with said back up plate threadedopening and each of said attaching bolt-receiving openings beingregisterable with a respective back up plate opening and the supportingmember threaded blind hole registering therewith, said punch retainerhaving a plurality of locating pins fixed thereto, each of said pinsbeing adapted to extend loosely through a respective opening in saidback up plate and tightly into a respective locating blind hole of saidsupporting member; and a plurality of attaching bolts, each of saidattaching bolts extending through a respective bolt-receiving openingand registering back up plate opening into threading engagement with arespective threaded blind hole of said support member, the thread sizeand diameter of said back up plate central threaded opening being thesame as the thread sizes and diameters of said supporting member blindholes, whereby any one of said attaching bolts is capable of beinginserted through said punch retainer central opening and screwed intosaid back up plate threaded opening and forced against said flat surfaceof said supporting member to move said punch retainer away from saidsupporting member and withdraw said pins from saidlocating blind holeswhen all the other attaching bolts are removed from said threaded blindholes of said supporting member.

References Cited in the file of this patent UNITED STATES PATENTS1,753,780 Fisher Apr. 8, 1930 1,804,935 J-acobus May 12, 1931 2,299,703Schwabe Oct. 20, 1942 2,305,076 Graham Dec. 15, 1942 2,635,338Dallenbach Apr. 21, 1953 2,684,527 Hedlund July 27, 1954

